Mattress



FIG. 1 is a first perspective view of the mattress;

FIG. 2 is a second perspective view of the mattress of FIG. 1;

FIG. 3 is an elevation of a first end of the mattress of FIG. 1;

FIG. 4 is an elevation of a second end of the mattress of FIG. 1,opposite the first end;

FIG. 5 is an elevation of a side of the mattress of FIG. 1, the oppositeside of which is identical in appearance; and,

FIG. 6 is a top plan view of the mattress of FIG. 1, the opposite sideof which is identical in appearance.

CLAIM The ornamental designs for a mattress, as shown and described.